Clinical CHF Flashcards
(38 cards)
What 2 formulas must we absolutely know?
- BP= CO x TPR
2. CO= HR x SV
What dictates the CO?
the filling time (preload), afterload, and inotropism (contractility).
Is the systemic vascular resistance high or low when the CO is low?
the systemic vascular resistance is high
What are the 2 neurohumoral responses that control systemic vascular resistance?
- sympathetic nervous system
2. renin-angiotensin aldosterone system (RAAS)
What happens to pressure if you increase volume?
you increase pressure also because they are in a direct linear relationship.
What happens if you have too little volume?
you stimulate the RAAS system to retain salt and increase volume and thus pressure.
* The body can overshoot though when it does this.
**What are the 2 types of heart failure?
- reduced= systolic dysfunction; EF
2. diastolic dysfunction
How do you treat CHF?
find the underlying etiology
What are the etiologies of CHF?
The loss of a critical quantity of functioning myocardial cells after injury to the heart due to:
- IHD
- hypertension
- Idiopathic cardiomyopathy
- Infections (viral myocarditis, Chagas’ disease)
- Toxins (alcohol or cytotoxic drugs)
- valvular disease
- prolonged arrhythmias
Where do you begin when a patient comes in?
with the history!
**What are the 4 controlling mechanisms of systolic dysfunction or reduced LV function?
- preload
- afterload
- inotropism (contractility)
- HR
What is the initial treatment for CHF?
to relieve the symptoms
**What is heart failure?
a complex clinical syndrome in which the heart is incapable of maintaining a CO adequate to accommodate metabolic requirements and the venous return.
What is the New York Heart Association (NYHA) classification system for heart failure?
- SOB with severe exertion
- SOB with moderate exertion
- SOB with mild exertion
- SOB with rest
* you can go from 1 to 2, 2 to 4, 4 to 1…
How does the American College of Cardiology rate heart failure?
A. Have the possibility of developing heart failure because you have risk factors.
B. You’re in heart failure and you don’t know it (due to compensatory mechanisms: RAAS and sympathetic NS).
C. You’re in active heart failure.
D. You have a cardiomyopathy and you will die.
What is the incidence (new cases each year) of heart failure?
a million
What should you think when end systolic or diastolic volume increases?
- neck vein distention
- hepatojugular reflux
- sacral or lower extremity edema
What should you think with pulmonary congestion?
- SOB
- CO is low
- systemic vascular resistance is up
- hypoperfusion
- cool to the touch distally
What are the symptoms of left ventricular dysfunction?
- dyspnea
- tachycardia
- cough
- hemoptysis
What are the physical signs of left ventricular dysfunction?
- basilar rales
- pulmonary edema
- S3 gallop
- pleural effusion
Cheyne-Stokes respiration
What are the 3 compensatory mechanisms of heart failure?
- Frank-Starling mechanism= increase volume, increase contractility.
- Neurohormonal Activation= SNS, RAAS, ADH
- Ventricular remodeling
So what does the body do when we have a decreased MAP?
it will compensate via the sympathetic nervous system (SNS) to increase this by increasing SV, HR, and TPR:
MAP= (HR x SV) x TPR
What are ACE inhibitors and ARBs?
afterload reducers. They inhibit the vasoconstriction and sodium retention that occurs in the kidney during sympathetic stimulation.
*Note: ARBs are NOT inferior to ACE inhibitors
Why do beta blockers PROLONG LIFE?
because they block the sympathetic stimulation on the heart that occurs during heart failure and would lead to myocardial toxicity, increased arrhythmias, and disease progression without them!